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US 7,253,499 B2Granted
III-V group nitride system semiconductor self-standing substrate, method of making the same and III-V group nitride system semiconductor wafer
AssigneeHitachi Cable, Ltd.
InventorMasatomo Shibata
Life of this patent
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Abstract
A III-V group nitride system semiconductor self-standing substrate has III-V group nitride system semiconductor single crystal with a hexagonal crystal system crystalline structure. The substrate is provided with a polished surface at every position of which crystal orientation perpendicular to the substrate surface is inclined 0.09 degrees or more from the C-axis direction of the substrate.
Claims15
A III-V group nitride system semiconductor self-standing substrate, comprising:
- III-V group nitride system semiconductor single crystal with a hexagonal crystal system crystalline structure,
- wherein the substrate is provided with a polished surface at every position of which crystal orientation perpendicular to the substrate surface is inclined 0.09 degrees or more from the C-axis direction of the substrate, and dispersion in the inclination from the C-axis direction is within ±1 degree.
A III-V group nitride system semiconductor wafer, comprising:
- a III-V group nitride system semiconductor self-standing substrate that comprises III-V group nitride system semiconductor single crystal with a hexagonal crystal system crystalline structure, wherein the substrate is provided with a polished surface at every position of which crystal orientation perpendicular to the substrate surface is inclined 0.09 degrees or more from the C-axis direction of the substrate, and dispersion in the inclination from the C-axis direction is within ±1 degree, and
- a III-V group nitride system semiconductor layer that is homo-epitaxially grown on the self-standing substrate.
A method of making a III-V group nitride system semiconductor self-standing substrate, comprising:
- providing an underlying substrate with a surface inclined θ degrees in a specific direction from a low index surface of the underlying substrate;
- growing a thick film of III-V group nitride system semiconductor single crystal on the underlying substrate;
- and
- separating the grown thick film from the underlying substrate to have the III-V group nitride system semiconductor self-standing substrate,
- wherein the thick film growing is conducted to satisfy the following expression:
- θ>sin−1(D/2R)+0.09 [degrees]
- where D is a diameter of the self-standing substrate after the separating and R is a curvature in distortion on the backside of the self-standing substrate.
4 more elements
A method of making a III-V group nitride system semiconductor self-standing substrate, comprising:
- growing a first single crystal gallium nitride film on a sapphire C-face substrate with a surface inclined θ degrees in a specific direction;
- depositing a metal film on the first gallium nitride film;
- thermally treating the sapphire C-face substrate with the metal film deposited thereon in an atmosphere containing hydrogen gas or hydride gas to have the first gallium nitride film with a void formed therein;
- growing a second single crystal gallium nitride film on the first gallium nitride film;
- and
- separating the second gallium nitride film from the first gallium nitride film and the sapphire substrate to have the III-V group nitride system semiconductor self-standing substrate,
- wherein the depositing of the second gallium nitride film is conducted to satisfy the following expression:
- θ>sin−1(D/2R)+0.09[degrees]
- where D is a diameter of the self-standing substrate after the separating and R is a curvature in distortion on the backside of the self-standing substrate.
6 more elements
A method of making a III-V group nitride system semiconductor self-standing substrate, comprising:
- growing a thick film of III-V group nitride system semiconductor single crystal on an underling substrate with an off-orientation of θ degrees;
- and
- separating the grown thick film of III-V group nitride system semiconductor single crystal from the underlying substrate to have the III-V group nitride system semiconductor self-standing substrate with a surface inclined a degrees with a dispersion of ±β degrees from a low index surface in a specific direction,
- wherein the growing step of the thick film of III-V group nitride system semiconductor single crystal is conducted to satisfy the following expression:
- α±β=n·θ±sin−1(D/2R)[degrees]
- where D is a diameter of the self-standing substrate after the separating, R is a curvature in distortion on the backside of the self-standing substrate, and n is a constant.
3 more elements
A method of making a III-V group nitride system semiconductor self-standing substrate, comprising:
- growing a first single crystal gallium nitride film on a sapphire C-face substrate with a surface inclined θ degrees in a specific direction;
- depositing a metal film on the first gallium nitride film;
- thermally treating the sapphire C-face substrate with the metal film deposited thereon in an atmosphere containing hydrogen gas or hydride gas to have the first gallium nitride film with a void formed therein;
- growing a second single crystal gallium nitride film on the first gallium nitride film;
- and
- separating the second gallium nitride film from the first gallium nitride film and the sapphire substrate to have the III-V group nitride system semiconductor self-standing substrate with a surface inclined a degrees with a dispersion of ±β degrees from a low index surface in a specific direction,
- wherein the depositing of the second gallium nitride film is conducted to satisfy the following expression:
- α±β=n·θ±sin−1(D/2R)[degrees]
- where D is a diameter of the self-standing substrate after the separating, R is a curvature in distortion on the backside of the self-standing substrate, and n is a constant.
6 more elements
Dependencies are inferred from the claim text.